1. Field of Invention
The invention relates to an electrical connector, and more particularly to an electrical connector connected to a circuit board.
2. Related Art
Referring to FIGS. 1 and 2, a conventional electrical connector assembly includes an electrical connector, a circuit board 25 and a main board 98.
The electrical connector has a plastic base 10 and a board engaging structure 20. The plastic base 10 had a slot 11 with an opening facing backwards, upper terminals 12 and lower terminals 13 are arranged in the slot 11 the plastic base 10 is fixed to the main board 98, and the upper terminals 12 and the lower terminals 13 respectively have pins electrically connected to the main board 98. The board engaging structure 20 is disposed in back of the plastic base 10 by a distance and fixed to the main board 98. The board engaging structure 20 has a positioning rod 21 and an elastic hook 22.
Upper and lower surfaces of the front end of the circuit board 25 are formed with connection points 26, and the rear end of the circuit board 25 is formed with an engagement hole 27.
When the circuit board 25 is to be connected to the connector, the connection points 26 at the front end of the circuit board 25 are slantingly inserted into the slot 11 of the electrical connector, and then the other end of the circuit board 25 is pressed down so that the positioning rod 21 is inserted into the engagement hole 27 of the circuit board 25 and the rear end of the circuit board 25 is engaged with the elastic hook 22.
The conventional structure has the following drawbacks.
First, the rear end of the circuit board 25 is elastically engaged with the elastic hook 22, and is thus not engaged very firmly because the elastic hook can be elastically opened. When the impact test is performed, the elastic hook 22 may be disengaged from the circuit board when the large impact force is applied.
Second, after the circuit board 25 is rotated to be horizontal, as shown in FIG. 2, the connection points 26 on the upper surface of the circuit board 25 are moved backwards, and the connection points 26 on the lower surface of the circuit board 25 are moved forwards. Thus, the oxidation layers on the connection points 26 on the upper surface of the circuit board 25 can be sufficiently scraped off (no wear occurs when the circuit board is inserted and moved forwards, and the wear occurs when the circuit board is rotated to be horizontal and then moved backwards), but the connection points 26 on the lower surface have no backward stroke and the wearing stroke of the horizontal motion is very short. So, the oxidation layers on the connection points 26 on the lower surface of the circuit board 25 and in contact with the lower terminals 13 cannot be sufficiently scraped off, and the electrical connection properties are poor.